CLASSICAL HIGH-TECH. Is this the ship that launched the golden age of Greece?

It's a debate that has raged since the fifth century: What did the ancient Greek warships look like? How well could they perform? Fewer than 400 ships had routed Xerxes' Persian fleet of 1,000 at Salamis in 480 BC, a victory that launched the golden age of Greece. The most recent answer to those questions is the Olympius, a reconstruction of a 170-oared trireme that took six years' work on the part of Britain's Trireme Trust and the Hellenic Navy.

Duplicating the remarkable shipbuilding technology used by the ancient Athenians to put maximum speed and maneuverability into the smallest possible space proved quite a challenge for the project's scholars, naval architects, and shipbuilders. For example, how do you fit 170 rowers - each with a 13-foot oar - into a 120-foot ship? It took untold amounts of research, 162 pages of specifications, $700,000 from the Hellenic Navy, and a crew of 200 to clarify the design, construction, and operational details.

Fifteen hundred years ago the historian Zozimus had concluded that the method of construction of the trireme (Greek trieres) ``was forgotten many years ago.'' Later studies from the 9th, 16th, and 18th centuries served only to confuse matters more until scholars could not even agree on whether ``tri'' (three) referred to the number of men per oar or the number of levels of oarsmen. An 1861 reconstruction built for the emperor Napoleon III was so bad it was sunk as target practice.

But a design worked out by Cambridge University classics scholar John Morrison and the British defense ministry's former chief naval architect, John Coates, cut through centuries of semantic debate using the former's half century of scholarship and the latter's naval science. Coates adjusted the design after subjecting it to the hypercritical arc lamp of discoveries from underwater archaeology at an international conference convened for the purpose in 1983.

As the ship began sea trials here last month, one rower remarked to Mr. Morrison: ``It must be a wonderful feeling to be afloat on your scholarship.''

Construction was lengthy - two years - and complex. The Athenians continually improved their ultralight triremes using techniques that have been lost. Now, as then, 20,000 pinned mortise-and-tenon joints were used to hold the hull together, saving weight and interior space for people instead of framing. Planks were pared down to a thickness normally used for boats half as long. The stretched, narrow hull had to be supported by a linen-rope hogging truss running from stem to stern.

The design had to allow for all this without benefit of evidence from an excavated trireme. No original example has ever been found: Historians conjecture that the boats were so lightly built that they swamped, but did not sink to the bottom.

The heart of the known evidence consists of a few worn bits of stone: The ship sheds that held the triremes are near what is now Zea, Greece. The length and width of the slipways define the length and width of the warship. The Lenormant Relief, a delicate rendering in pink granite from the 5th century BC that shows a portion of a trireme, adds still more detail. Underwater excavation of two contemporary merchant vessels from Cyprus and Sicily, naval inventories, classical literature, and pottery provide confirming (and some contradictory) evidence as to hull shape, joint spacing, oar length, number of rowers per level, battle strategy, and a hundred other details.

``If you integrate all this evidence within what is necessarily a very lightly built ship,'' says John Coates, ``there is very little room for artistic interpretation. Change any factor very much and the results of the calculations tell you the thing will come apart or function inefficiently. It is because the trieres is so sensitive we can use [this] reconstruction to improve our design understanding and test our interpretations of classical naval engagements.''

Last month, the first sea trials of the design began the painstaking task of figuring out, detail by detail, how and why this kind of ship became the cornerstone of classical Greek hegemony, science, literature, and philosophy. Athens succeeded because its ships were faster, more maneuverable, and had more highly skilled crews than other warships of the day.

In order for the three tiers of oars to be balanced, for example, designers of the Olympius concluded that the top and middle rows (or thranite and zygian, respectively) had to be thinner so that the handle pressure equaled that of the lowest tier (thalamian). Counterweighting the oars on the top levels bore this out: ``The two to three pounds pressure reduction has made all the difference in the world!'' rowers commented.

Similar small changes, and a more precisely selected crew, should enable the Olympius to exceed its current top speed of 7 knots at 38 strokes per minute and readily achieve the classical Athenian best of 9 to 10 knots. It also puts within reach the classically attested, nonstop 120-plus mile journeys at 7 to 8 knots.

The Olympius' current best is 5 knots over distance. It is through these adjustments to details and follow-up sea trials that Olympius will tell us how close the best of experimental archaeology can bring us to the glories of ancient Greece.